Thin film deposition apparatus

ABSTRACT

A reaction chamber includes a reactor wall, a susceptor contacting the reactor wall to define a reaction space and a gas flow control device and a showerhead member stacked between the reactor wall and the susceptor. The showerhead member includes a gas channel and a showerhead. Penetration holes are formed through a protruding lateral portion of the gas flow control device, and the reactor wall and a lateral portion of the showerhead member are spaced apart from each other to form a gas discharge path. Gas remaining in the gas discharge path is discharged through the penetration holes and a gas outlet formed in an upper portion of the reactor wall. Because of the reaction space and the gas discharge path, unnecessary regions are removed to rapidly change gases from one to another, and thus atomic layer deposition may be performed with high efficiency and productivity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/202,468 filed on Jul. 5, 2016, which claims the benefit of KoreanPatent Application No. 10-2015-0096795 filed on Jul. 7, 2015, the entiredisclosure of both of which are hereby incorporated by reference.

BACKGROUND 1. Field

One or more embodiments relate to a gas flow control device, ashowerhead assembly including the gas flow control device, and asemiconductor manufacturing apparatus (such as a thin film depositionapparatus) including the showerhead assembly.

2. Description of the Related Art

One or more exemplary embodiments relate to a semiconductormanufacturing apparatus (such as a deposition apparatus), and moreparticularly, to a reaction chamber in which chemical reactions occur.

A reaction chamber of deposition apparatus provides a space in whichchemical reactions occur, and various reaction chambers have beendeveloped. Examples of such reaction chambers include a showerhead-typereaction chamber in which reaction gas is supplied in a directionperpendicular to a substrate, and a side flow-type reaction chamber inwhich reaction gas is supplied in a direction parallel to a substrate.In the showerhead-type reaction chamber, reaction gas is uniformlysupplied to a reactor in a center-to-edge direction, and thus arelatively uniform thin film is formed. The side flow-type reactionchamber has a relatively simple structure, thereby enabling rapidswitching between reaction gases and making it possible to reduce areaction space.

SUMMARY

One or more embodiments include a reaction chamber, for example, ashowerhead-type reaction chamber including a showerhead and an auxiliarydevice. The reaction chamber provides a reaction space optimally reducedin size for atomic layer deposition, and exhaust gas is rapidlydischarged from the reaction chamber.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to one or more embodiments, a gas flow control device isprovided. The gas flow control device may include: a plate including agas inlet port and extending from the gas inlet port; and a sidewallprotruding from the plate and including a plurality of holes formedtherethrough. Optionally, the plate may include an insulative material.

According to an embodiment, in the gas flow control device, a spaceconcave from the sidewall may be formed by the plate and the sidewall,and a gas discharge path space may be defined from the plurality ofholes to the concave space.

According to one or more embodiments, a showerhead assembly is provided.The showerhead assembly may include: the gas flow control device; and ashowerhead member connected to the gas inlet port from a bottom side ofthe plate.

According to an embodiment, the showerhead assembly may include a gaschannel and a showerhead, and the gas channel may be positioned betweenthe gas inlet port and the showerhead and connected to the showerhead bymechanical connectors.

According to another embodiment, in the showerhead assembly, a gas flowpath may be formed between the gas channel and the showerhead. Inaddition, a gas inlet path (refer to a center region of the gas channel307 in the accompanying drawings) connecting the gas inlet port of thegas flow control device to the gas flow path may be formed.

According to one or more embodiments, a semiconductor manufacturingapparatus (such as a reaction chamber) includes: a reactor wall; a gasflow control device, a showerhead member, and a susceptor. A gas inletand a gas outlet are provided on an upper portion of the reactor wall,and the gas inlet is connected to a gas inlet port formed through centerportions of the reactor wall, the gas flow control device and theshowerhead member so as to supply reaction gas to the showerhead member.The gas flow control device includes: a protruding sidewall throughwhich a plurality of penetration holes are formed; and a platesurrounded by the sidewall. A gas discharge path (that is, a gasdischarge path space) is formed in a region between the gas flow controldevice and the reactor wall and a region between a sidewall of theshowerhead member and the reactor wall, and reaction gas supplied to asubstrate placed on the susceptor through the showerhead member isdischarged to the gas outlet provided on the upper portion of thereactor wall through the gas discharge path and the penetration holesformed through the sidewall of the gas flow control device. The gasoutlet is asymmetric with the gas inlet port formed through the centerportion of the gas flow control device, and the size of the penetrationholes and intervals between the penetration holes are varied accordingto the positions of the penetration holes relative to the gas outlet soas to obtain uniform gas discharge efficiency. In the semiconductormanufacturing apparatus (such as a reaction chamber) of the embodiment,the gas flow control device and the showerhead member are stacked, andgrooves are formed in a region between the gas flow control device andthe reactor wall and a region between the gas flow control device andthe showerhead member to receive sealing members such as O-rings. Thereactor wall and the showerhead member are spaced apart from each otherto form the gas discharge path. Radio frequency (RF) rods are insertedthrough other penetration hole formed through the gas flow controldevice and are connected to the showerhead member so as to supply RFpower to the showerhead member during a plasma process.

According to an embodiment, in the semiconductor manufacturingapparatus, the gas inlet and the gas outlet may be connected to a toplid. In addition, the top lid may include a heating element.

According to one or more embodiments, a semiconductor manufacturingapparatus includes: an external chamber including at least two reactionchambers; at least one gas supply unit which the at least two reactionchambers share; and at least one discharge pump configured to dischargegas.

For example, the semiconductor manufacturing apparatus may include: atop lid including at least two gas inlets and at least two gas outlets;and at least two reaction chambers each connected to the top lid inconnection with at least one of the gas inlets and at least one of thegas outlets, wherein the reaction chambers share a gas supply unitsupplying at least one of raw-material gases and reaction gases and atleast one discharge pump.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a view illustrating a reaction chamber according to anembodiment;

FIG. 2 is a view illustrating how reaction gas flows in the reactionchamber according to an embodiment;

FIG. 3A is a perspective view illustrating a gas flow control deviceaccording to an embodiment;

FIG. 3B is a cross-sectional view illustrating an assembled structure ofthe gas flow control device and a showerhead member according to anembodiment;

FIG. 4A is a partial cross-sectional view illustrating the reactionchamber according to an embodiment;

FIG. 4B is a partial cross-sectional view illustrating the reactionchamber according to another embodiment;

FIG. 4C is a partial cross-sectional view illustrating the reactionchamber according to another embodiment;

FIG. 5A is a plan view illustrating the gas flow control deviceaccording to an embodiment;

FIG. 5B is a plan view illustrating the gas flow control deviceaccording to another embodiment;

FIG. 6 is a cross-sectional view illustrating a reaction chamberaccording to another embodiment;

FIG. 7A is a cross-sectional view illustrating a reaction chamberaccording to another embodiment;

FIG. 7B is another cross-sectional view illustrating the reactionchamber depicted in FIG. 7A from another direction; and

FIG. 8 is a cross-sectional view illustrating reaction chambersaccording to another embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present description. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

Characteristics of the inventive concept and implementation methodsthereof will be clarified through the following descriptions given withreference to the accompanying drawings. The embodiments may, however,have different forms and should not be construed as being limited to thedescriptions set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the inventive concept to those skilled in the art.Therefore, the scope of the inventive concept should be defined by theclaims.

Hereinafter, embodiments will be described with reference to theaccompanying drawings.

First, a deposition apparatus will now be described according to anembodiment with respect to FIG. 1. FIG. 1 is a cross-sectional viewillustrating a reaction chamber 100 according to an embodiment.Referring to FIG. 1, as a reactor wall 101 and a susceptor 103 arebrought into contact with each other, a reaction space 125 is formed inthe reaction chamber 100. A gas flow control device 105 and a showerheadmember (gas injector) 109 are disposed between the upper portion of thereactor wall 101 and the susceptor 103. The showerhead member 109 may bea one-piece member or may be a multi-piece member including a separatepart in which gas injection holes 133 are formed. The gas flow controldevice 105 and the showerhead member 109 are stacked, and the gas flowcontrol device 105 includes a sidewall 123 in which a plurality ofpenetration holes 111 are formed. Grooves 127, 129, and 131 are formedin a region between the reactor wall 101 and the gas flow control device105 and a region between the gas flow control device 105 and theshowerhead member 109 so as to receive sealing members such as O-rings.Owing to vacuum sealing by the sealing members, external gases may notpermeate into the reaction chamber 100, or reaction gases in thereaction space 125 or gases remaining in gas discharge paths may notleak to unintended regions.

The showerhead member 109 may be used as an electrode during a plasmaprocess. To this end, the showerhead member 109 may include a metallicmaterial such as aluminum (Al). In addition, radio frequency (RF) rods713 (refer to FIG. 7B) are mechanically connected to the showerheadmember 109 through RF rod holes 303 (refer to FIG. 3A) formed through anupper portion of the reactor wall 101 and the gas flow control device105, so as to supply plasma generated by an external plasma generator(not shown) to the showerhead member 109. In addition, the gas flowcontrol device 105 may include an insulative material such as a ceramicmaterial so as to insulate the showerhead member 109, used as a plasmaelectrode, from the reactor wall 101. As shown in FIG. 1, a gas inletport 113 is formed through the upper portion of the reactor wall 101 anda center portion of the gas flow control device 105, and a gas flow path119 is additionally formed in the showerhead member 109. Thus, reactiongas supplied from an external gas supply unit (not shown) through thegas inlet port 113 is uniformly distributed to the gas injection holes133 of the showerhead member 109. In addition, as shown in FIG. 1, a gasoutlet 115 is provided at the upper portion of the reactor wall 101 inan asymmetric relationship with the gas inlet port 113. However, the gasoutlet 115 and the gas inlet port 113 may be symmetrically arranged (notshown). In addition, the reactor wall 101 is spaced apart from sidewallsof the gas flow control device 105 and the showerhead member 109, andthus a gas discharge path 117 may be formed therebetween. After aprocess is performed, remaining gas may be discharged through the gasdischarge path 117.

FIG. 2 is a view illustrating how reaction gas flows in the reactionchamber 100 according to an embodiment. In FIG. 2, arrows indicate gasflows. Reaction gas supplied from the external gas supply unit (notshown) to the gas inlet port 113 may uniformly flow to the gas injectionholes 133 of the showerhead member 109 through the gas flow path 119.The reaction gas may undergo a chemical reaction in the reaction space125 or on a substrate (not shown) to form a thin film on the substrate.After a thin film is formed, remaining gas may flow to an internal spaceof the gas flow control device 105 after passing through the gasdischarge path 117 formed between the reactor wall 101 and the sidewallof the showerhead member 109 and passing through the penetration holes111 formed in the sidewall 123 of the gas flow control device 105, andthen the remaining gas may be discharged through the gas outlet 115.

Hereinafter, each part of the reaction chamber 100 will be describedwith reference to FIGS. 3A and 3B.

FIG. 3A is a perspective view illustrating the gas flow control device105 according to an embodiment. Referring to FIG. 3A, the gas flowcontrol device 105 includes the sidewall 123, the gas inlet port 113, aplate 301 surrounded by the sidewall 123, the RF rod holes 303, screwholes 305, the penetration holes 111, and the groove 127 accommodating asealing member such as an O-ring. In FIG. 3A, the plate 301 has aconcave inner portion surrounded by the sidewall 123. The gas inlet port113 is located at a portion of the gas flow control device 105 tointroduce external reaction gas, and the screw holes 305, the number ofwhich is at least two, are formed around the gas inlet port 113 toreceive mechanical connectors such as screws 715 (refer to FIG. 7B) andthus to connect the gas flow control device 105 and the showerheadmember 109 to each other. The RF rod holes 303 are formed in portions ofthe gas flow control device 105, and thus the RF rods 713 (refer to FIG.7B) connected to an external plasma supply unit (not shown) may beconnected to the showerhead member 109 under the gas flow control device105 through the RF rod holes 303.

In FIG. 3A, two RF rod holes 303 are formed to improve the uniformity ofplasma power in the reaction space 125 by introducing the RF rod torespective holes 303. However, unlike in FIG. 3A, one or more than twoRF rods 713 may be used, and RF rod holes 303 corresponding to the RFrods 713 may be formed. Furthermore, referring to FIG. 3A, the RF rodholes 303 are formed between the sidewall 123 and the screw holes 305.However, the inventive concept is not limited thereto. For example, likethe screw holes 305, the RF rod holes 303 may be disposed around the gasinlet port 113.

Gas remaining after reacting with a substrate may flow to the plate 301of the gas flow control device 105 through the gas discharge path 117and the penetration holes 111 formed in the sidewall 123 of the gas flowcontrol device 105. Then, the gas may flow across an internal space ofthe plate 301 toward the gas outlet 115 where the gas may be dischargedto the outside. A sealing member such as an O-ring is inserted into thegroove 127 formed in an upper side of the sidewall 123 for vacuumsealing between the reactor wall 101 and the gas flow control device105, and thus gas remaining in the gas discharge path 117 may beintroduced into the plate 301 of the gas flow control device 105 onlythrough the penetration holes 111. Furthermore, although not illustratedin FIG. 3A, other grooves 717 and 721 (refer to FIG. 7B) may be formedin a region between an upper end of the reactor wall 101 and the RF rodholes 303 and a region between the upper end of the reactor wall 101 andthe screw holes 305, so as to receive sealing members such as O-rings.Therefore, vacuum sealing may be provided to prevent remaining gas fromleaking to the outside through unintended paths.

FIG. 3B is a cross-sectional view illustrating a showerhead assemblyformed by stacking the gas flow control device 105 and the showerheadmember 109 together. Referring to FIG. 3B, the showerhead member 109 isa multi-piece member in which a gas channel 307 and a showerhead 309 arestacked together. The gas channel 307 and the showerhead 309 areconnected using mechanical connectors such as screws 311. If theshowerhead member 109 is used as an electrode during a plasma process,the showerhead 309 may include a metallic material. In addition, the RFrods 713 (refer to FIG. 7B) may be mechanically connected to the gaschannel 307 through the RF rod holes 303 (refer to FIG. 7B).

FIGS. 4A, 4B, and 4C are partial cross-sectional views illustrating thereaction chamber 100 according to embodiments. Referring to FIG. 4A, thereactor wall 101 and the showerhead member 109 are spaced apart fromeach other to form the gas discharge path 117, and the penetration holes111 are formed in the sidewall 123 of the gas flow control device 105.The grooves 127 and 131 are formed in an upper portion of the sidewall123 making contact with the reactor wall 101 and a contact portion ofthe showerhead member 109, and thus sealing members such as O-rings maybe inserted into the grooves 127 and 131 for vacuum sealing. Therefore,gas remaining in the gas discharge path 117 may be introduced into thegas flow control device 105 only through the penetration holes 111.Referring to FIG. 4A, the penetration holes 111 are formed in adirection perpendicular to the gas discharge path 117. However, asillustrated in FIG. 4B, entrances 401 of the penetration holes 111 maybe inclined toward the gas discharge path 117. In this case, the angle θof the entrances 401 of the penetration holes 111 relative to adirection in which remaining gas flows in the gas discharge path 117 maybe less than a right angle. Thus, turbulent flow may be reduced aroundthe entrances 401, and accordingly, the decrease of gas dischargeefficiency may be prevented. In addition, as illustrated in FIG. 4C, aportion of the sidewall 123, in which the penetration holes 111 areformed, may have a width (A) less than the width (B) of an edge portionof the gas flow control device 105. In this case, remaining gas may flowdirectly into entrances 402 of the penetration holes 111 without passingthrough a bent path. Therefore, when remaining gas flows into thepenetration holes 111, laminar flow may be maintained around theentrances 402 of the penetration holes 111 without turbulent flow, andthus the remaining gas may be smoothly discharged with high efficiency.Although not shown, the shape of the reactor wall 101 or the gas flowcontrol device 105 may be modified to prevent turbulent flow. Forexample, an edge portion C (refer to FIG. 4C) of the gas flow controldevice 105 may be chamfered.

In addition to structures illustrated in the accompanying drawings,various modifications may be made within the scope of the inventiveconcept. For example, in the embodiments illustrated in FIGS. 4A to 4C,the sidewall 123 protrudes in a direction different from a direction inwhich the plate 301 extends. However, the sidewall 123 may protrude inthe same direction as the direction in which the plate 301 extends. Inthis case, the penetration holes 111 may be formed through the sidewall123 in a direction different from the direction in which the plate 301extends.

FIGS. 5A and 5B are plan views of the gas flow control device 105,illustrating the distribution and size of the penetration holes 111formed in the sidewall 123 of the gas flow control device 105. Referringto FIG. 5A, the penetration holes 111 have the same size. However, thedistance between the penetration holes 111 formed in the sidewall 123 isgreater in a region A adjacent to the gas outlet 115 than in regions Band C distant from the gas outlet 115. Referring to FIG. 5A, sincepenetration holes 111 located in the region C opposite the gas outlet115 have a relatively low degree of gas discharge efficiency, thepenetration holes 111 are densely arranged. However, since penetrationholes 111 located in the region A adjacent to the gas outlet 115 have arelatively high degree of gas discharge efficiency, the penetrationholes 111 are less densely arranged. Therefore, gas discharge efficiencymay be uniform as a whole. Referring to FIG. 5B, although thepenetration holes 111 are arranged at regular intervals, the penetrationholes 111 have different sizes according to their positions relative tothe gas outlet 115. That is, since penetration holes 111 located in theregion A adjacent to the gas outlet 115 have a relatively high degree ofgas discharge efficiency, the penetration holes 111 have a relativelysmall size. However, since penetration holes 111 located in the region Copposite the gas outlet 115 have a relatively low degree of gasdischarge efficiency, the penetration holes 111 have a relatively largesize. Therefore, gas discharge efficiency may be uniform as a whole.

Although one gas outlet 115 is illustrated in FIGS. 5A and 5B, aplurality of gas outlets 115 may be provided. In this case, the gasoutlets 115 may be symmetrically or asymmetrically arranged. Inaddition, as described above, at least one of the size of thepenetration holes 111, the shape of the penetration holes 111, and thedistance between the penetration holes 111 may be adjusted to obtainuniform gas discharge efficiency. For example, penetration holes 111relatively adjacent to the gas outlet 115 may have a relatively smallsize or may be arranged at relatively large intervals, compared topenetration holes 111 relatively distant from the gas outlet 115.

FIG. 6 is a cross-sectional view illustrating a reaction chamber 100according to another embodiment. FIG. 6 illustrates a dual chamberstructure in which the reaction chamber 100 is enclosed by an externalchamber 601. The reaction chamber 100 is mechanically fixed to an upperend of the external chamber 601, that is, a top lid of the externalchamber 601. The internal pressure of the external chamber 601 may beset to be lower than the internal pressure of the reaction chamber 100,so as to prevent gas such as argon gas filled in the external chamber601 from permeating into the reaction chamber 100 through a gap betweena reactor wall 101 and a susceptor 103. An entrance (not shown, refer toFIG. 8) is formed in a sidewall of the external chamber 601 to transfera substrate to/from a reaction chamber 1100. The susceptor 103 issupported by a susceptor support 605. The susceptor support 605 includessubstrate support pins (not shown). The susceptor support 605 isvertically movable and rotatable. Therefore, when a substrate isloaded/unloaded, the susceptor support 605 is lowered to open a reactionspace 125. For example, a substrate is lifted by the substrate supportpins (not shown), and a carrier such as a transfer arm is inserted intothe external chamber 601 through the entrance (not shown) formed in thesidewall of the external chamber 601 so as to unload the substrate.During a process, the susceptor support 605 is lifted, and at the sametime, the substrate support pins on which a substrate is supported arelowered to place the substrate on the susceptor 103. Then, the susceptor103 is brought into contact with a lower portion of the reactor wall101, thereby forming the reaction space 125.

FIGS. 7A and 7B are views illustrating a modification of the reactionchamber 100 depicted in FIG. 6, according to another embodiment.Referring to FIG. 7A, a reactor wall 101 of a reaction chamber 100 isconnected to a top lid 701 on an upper end of an external chamber byusing mechanical connectors such as screws 707. In addition, a heatersuch as a heating element may be arranged on an upper end of the reactorwall 101 to heat the reactor wall 101. If the reactor wall 101 is heatedusing the heating element, gas remaining in a gas discharge path 117 oraround a gas flow control device 105 may be rapidly heated or convertedinto a hard film, and thus the remaining gas may not act as a pollutantfloating in the reaction chamber 100, and contamination of a reactionspace may be prevented. Referring to FIG. 7A, a gas inlet 705 isadditionally provided on an upper end of a gas inlet port 113. If aplurality of gas inlet holes (not shown) are formed on the side of thegas inlet 705, gas may be supplied to the reaction chamber 100 in largeamounts. In addition, referring to FIG. 7A, unlike the one-pieceshowerhead member 109 depicted in FIG. 1, a showerhead member 109 formedof multiple separable parts is used. For example, the showerhead member109 has a stacked structure including a gas channel 307 and a showerhead309 connected to each other by mechanical connectors such as screws.Since the multi-piece showerhead member 109 has a multi-piece structure,installation, separation, and periodic maintenance of the showerhead 309may easily be performed.

FIG. 7B is another cross-sectional view illustrating the reactionchamber 100 depicted in FIG. 7A from another direction. Referring toFIG. 7B, the showerhead member 109 is connected to the gas flow controldevice 105 by a mechanical connectors such as screws 715. Grooves may beformed in a region between a sidewall of the gas flow control device 105and an upper end of the reactor wall 101, a region between protrusionsaround RF rod holes 303 and the upper end of the reactor wall 101, and aregion between a protrusion around screw holes 305 and the upper end ofthe reactor wall 101, and sealing members such as O-rings may beinserted into the grooves for vacuum sealing.

FIG. 8 is a cross-sectional view illustrating reaction chambers 100according to another embodiment. Referring to FIG. 8, a plurality ofreaction chambers 100 are disposed in a chamber inner region 805 formedby a top lid 801 and an external chamber 803. A gas flow control device,a showerhead member, a gas inlet port, and a gas outlet of each of thereaction chambers 100 are disposed on the top lid 801. The reactionchambers 100 share the same gas supply unit and the same discharge pump,and thus the same process may be performed on a plurality of substratesat the same time so as to increase productivity.

The same process may be performed on a plurality of substrates at thesame time as follows. First, a carrier such as a transfer arm isinserted into the chamber inner region 805 through an entrance of theexternal chamber 803 so as to load substrates on a plurality ofsusceptors 103. Thereafter, the chamber inner region 805 of the externalchamber 803 is evacuated or filled with an inert gas such as argon gas.Next, the susceptors 103 are brought into contact with lower sides ofreactor walls, thereby forming reaction spaces. The pressure of thechamber inner region 805 may be set to be lower than the internalpressure of the reaction chambers 100.

Alternatively, the reaction chambers 100 may not share the gas supplyunit and the discharge pump but may be connected to individual gassupply units and discharge pumps so as to perform different processes atthe same time. For example, while sequentially moving a substrate to thereaction chambers 100, a composite thin film forming process may beperformed to deposit thin films on the substrate. In this case, thecomposite thin film forming process may be rapidly performed whileminimizing exposure to air or waiting time.

As described above, according to the one or more of the aboveembodiments, reaction gas is uniformly supplied to a substrate in thereaction chamber, and thus a uniform thin film may be formed on thesubstrate. In addition, since the gas discharge path is formed along anupper portion of the showerhead, unnecessary spaces may be removed toreduce the size of the reaction space. As a result, reaction gases maybe rapidly changed from one to another, and contamination caused byremaining gases may be reduced, thereby making it possible to perform anatomic layer deposition process with high productivity and efficiency.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the inventive concept as definedby the following claims.

What is claimed is:
 1. A gas flow control device for controlling a gasflow input to and output from a reaction space inside a reaction chamberto form a thin film on a substrate, the gas flow control devicecomprising: a plate comprising a central portion, a peripheral portionand a middle portion interposed between the central portion and theperipheral portion; a gas inlet port formed though the central portionof the plate, wherein the gas inlet port is configured to receive andsupply a first flow of a reaction gas to the reaction space via ashowerhead assembly such that the first flow of the reaction gasundergoes a chemical reaction in the reaction space; a sidewallprotruding from the middle portion of the plate; a plurality of holesformed through the side wall, wherein the plurality of holes areconfigured to receive from the reaction space a second flow of thereaction gas remaining after the chemical reaction is complete anddischarge the received second flow of the reaction gas to the outside ofthe reaction chamber; a fixing hole formed through the middle portion ofthe plate, wherein the fixing hole is configured to receive a mechanicalconnector for connecting the gas flow control device to the showerheadassembly; and a rod hole formed through the middle portion of the plateand configured to receive a radio frequency (RF) rod for supplying RFpower to the showerhead assembly.
 2. The gas flow control device ofclaim 1, wherein the plate and the sidewall are configured such that aspace over the middle portion of the plate connects the plurality ofholes to a gas outlet of the reaction chamber to forma gas dischargepath when the gas flow control device is installed in the reactionchamber.
 3. The gas flow control device of claim 1, wherein theplurality of holes comprise first holes and second holes, and at leastone of a size of the first holes, a shape of the first holes, and adistance between the first holes is different from that of the secondholes.
 4. The gas flow control device of claim 1, wherein the sidewallhas a shape configured to accommodate a sealing member.
 5. The gas flowcontrol device of claim 1, wherein the fixing hole is closer to the gasinlet port than the sidewall.
 6. The gas flow control device of claim 1,wherein the gas inlet port has a diameter larger than each of diametersof the plurality of holes.
 7. The gas flow control device of claim 1,wherein the fixing hole is disposed between the gas inlet port and theplurality of holes.
 8. The gas flow control device of claim 1, whereinthe rod hole is disposed between the fixing hole and the plurality ofholes.
 9. The gas flow control device of claim 1, wherein the rod holehas a diameter larger than that of the fixing hole.
 10. The gas flowcontrol device of claim 1, wherein the rod hole comprises a plurality ofrod holes, wherein the fixing hole comprises a plurality of fixingholes, and wherein the number of the plurality of fixing holes isgreater than that of the plurality of rod holes.
 11. The gas flowcontrol device of claim 1, wherein the rod hole comprises a plurality ofrod holes, and wherein at least two of the fixing holes aresymmetrically disposed with respect to the gas inlet port.
 12. The gasflow control device of claim 1, wherein the rod hole comprises aplurality of rod holes, and wherein the number of the plurality of holesof the sidewall is greater than that of the plurality of rod holes. 13.A reaction chamber for forming a thin film on a substrate, the reactionchamber comprising: a reaction space configured to deposit the thin filmon the substrate using a reaction gas; a showerhead assembly configuredto supply the reaction gas to the reaction space; and a gas flow controldevice connected to the showerhead assembly and configured to control aflow of the reaction gas input to and output from the reaction space,wherein the gas flow control device comprises: a plate comprising acentral portion, a peripheral portion and a middle portion interposedbetween the central portion and the peripheral portion; a gas inlet portformed though the central portion of the plate, wherein the gas inletport is configured to receive and supply a first flow of a reaction gasto the reaction space via a showerhead assembly such that the first flowof the reaction gas undergoes a chemical reaction in the reaction space;a sidewall protruding from the middle portion of the plate; a pluralityof holes formed through the side wall, wherein the plurality of holesare configured to receive from the reaction space a second flow of thereaction gas remaining after the chemical reaction is complete anddischarge the received second flow of the reaction gas to the outside ofthe reaction space; a fixing hole formed through the middle portion ofthe plate, wherein the fixing hole is configured to receive a mechanicalconnector for connecting the gas flow control device to the showerheadassembly; and a rod hole formed through the middle portion of the plateand configured to receive a radio frequency (RF) rod for supplying RFpower to the showerhead assembly.
 14. The reaction chamber of claim 13,wherein the plate and the sidewall are configured such that a space overthe middle portion of the plate connects the plurality of holes to a gasoutlet of the reaction chamber to form a gas discharge path when the gasflow control device is installed in the reaction chamber.
 15. Thereaction chamber of claim 13, wherein the gas inlet port has a diameterlarger than each of diameters of the plurality of holes.
 16. Thereaction chamber of claim 13, wherein the fixing hole is disposedbetween the gas inlet port and the plurality of holes.
 17. The reactionchamber of claim 13, wherein the rod hole is disposed between the fixinghole and the plurality of holes.
 18. A showerhead assembly for forming athin film on a substrate, the showerhead assembly comprising: ashowerhead; and a gas flow control device connected to the showerheadand configured to control a flow of the reaction gas input to and outputfrom a reaction space inside a reaction chamber, wherein the gas flowcontrol device comprises: a plate comprising a central portion, aperipheral portion and a middle portion interposed between the centralportion and the peripheral portion; a gas inlet port formed though thecentral portion of the plate, wherein the gas inlet port is configuredto receive and supply a first flow of a reaction gas to the reactionspace via a showerhead assembly such that the first flow of the reactiongas undergoes a chemical reaction in the reaction space; a sidewallprotruding from the middle portion of the plate; a plurality of holesformed through the side wall, wherein the plurality of holes areconfigured to receive from the reaction space a second flow of thereaction gas remaining after the chemical reaction is complete anddischarge the received second flow of the reaction gas to the outside ofthe reaction chamber; a fixing hole formed through the middle portion ofthe plate, wherein the fixing hole is configured to receive a mechanicalconnector for connecting the gas flow control device to the showerheadassembly; and a rod hole formed through the middle portion of the plateand configured to receive a radio frequency (RF) rod for supplying RFpower to the showerhead assembly.
 19. The showerhead assembly of claim18, wherein the gas inlet port has a diameter larger than each ofdiameters of the plurality of holes.
 20. The showerhead assembly ofclaim 18, wherein the rod hole comprises a plurality of rod holes, andwherein the number of the plurality of holes of the sidewall is greaterthan that of the plurality of rod holes.